All Answers

There is not a way to verify that a new board is good or not. AS far as testing and diagnosing a control board in a unit goes, the best test is power in and power out. At the J1 connector at the board. You are checking from line to ground at black and green. Check from black to light blue which is pin 1 and 3. This is line and neutral. You should get 120v. If not your loosing a neutral somewhere. Go back to the outlet and check to see if you have proper voltage. line to neutral and line to ground should be 120v. neutral to ground should be 0v . There is a diagnostic mode on the tech sheet, but I most likely will not work with the unit not powering up. The unit should start up after plugging the unit back in after the repair. I have seen any communication errors on these units that usually result in the main board being the fault. Its a communication error between the UI board and main board. Above I have attached the tech sheet previously if you need to take a look at it. IF the inverter board is bad it should not cause everything to shut down. Power piggy backs off of the inverter board to the main board so it should not make a difference. Going back to the main board you installed. I show that is not the correct part number you installed. The main board on the bottom of the unit is 241996361. You may have installed the wrong board. The part number you are providing is coming back as invalid. not even listed as a part. I have installed this board before and pinched a wire which shorted out and caused the new board to go bad. IF you had a power surge to this unit it could have also taken out multiple boards. I dont think extending your time will be an issue. I will check with my manager.